Recently, with improvement in performance of physical machines, a virtualization technique of integrating multiple virtual machines (hereinafter, also referred to as VM) into a single physical machine has been studied. For example, the virtualization technique allows, for example, virtualization software (hypervisor) to allocate physical machines to multiple virtual machines and enables providing of a service based on application programs (hereinafter, also referred to as applications) installed in the virtual machines.
When a provider who provides a service using virtual machines constructs a system, a template which is an assembly of information to be used to construct the system may be created in advance. The template is created, for example, based on information of a system previously constructed by the provider. The provider can reduce time or effort for constructing the system by constructing the system based on the template. A provider (seller) who provides the service based on the constructed system may prepare the template.
When a system is constructed based on a template, the system is generally constructed in physical machine groups (for example, physical machine groups equipped in the same data center) which are equipped as close to each other as possible in order to prevent an increase in load of a communication line between data centers. However, for example, in physical machine groups equipped in a single data center, there is a case in which resources to be used to construct the system is not sufficiently secured. In this case, the provider needs to construct a system to be laid across physical machine groups equipped in multiple data centers.
When a system is constructed to be laid across physical machine groups equipped in multiple data centers, communication between the data centers occurs. Accordingly, the provider constructs a system in a state in which devices such as a firewall (hereinafter, also referred to as FW) or a router of which information is not included in the template are added (for example, see Japanese Laid-open Patent Publication No. 2009-278277).